Solid-liquid Extraction of Soluble Carbohydrates from Soybean Meal: an Experimental Study, Kinetics, and Modeling

Abstract

Abstract Soybean Protein concentrate is a product from the soy processing industry with high value, but to obtain it is necessary to evaluate the favorable operational conditions to extract soluble carbohydrate from soybean meal with low loss of protein. The solid-liquid extraction of soluble carbohydrates compounds from soybean meal was evaluated in view to estimate the influence of the operational parameters and the kinetic of soluble carbohydrates extraction. The influence of temperature (45-65°C), mean diameter (0.6-1.4 mm), and mass/solvent ratio (5-15 mg/mL) was investigated by Box-Behnken 33-1 central composite design. The soluble carbohydrate compounds over time were investigated using three mathematical models (equilibrium-dependent, Peleg, and intra-particle diffusion). The results at Box-Behnken indicated that higher temperatures and DSM to the solvent ratio resulted in increased extraction yield of the soluble carbohydrates, while the DSM particle size showed a minor influence. According to the kinetics data, the extraction process approached equilibrium after around 120-180 min. The conditions that maximized the extraction were 60°C and DSM to the solvent ratio of 10 mg/mL, resulting in the reduction of the total soluble total carbohydrate content in DSM of 29.5% to 15.1%, resulting in soy protein concentration in DSM of 65.8%, compatible with the standard protein content of SPC product. The intraparticle diffusion model was found to be the most suitable to describe the extraction process due to the best fit with the experimental data.

Keywords

• Deffated soybean meal
• batch process extraction
• stachyose
• raffinose
• intraparticle diffusion